As processes for producing a carbonate compound which does not use phosgene having toxicity, the following processes are known.
(1) A process for producing a cyclic carbonate by reacting carbon dioxide gas with an alkene oxide in the presence of a catalyst (see, e.g., Patent Document 1).
(2) A process for producing by an ester exchange reaction of a cyclic carbonate or dimethyl carbonate with an alcohol in the presence of an ester exchange reaction catalyst (see, e.g., Non-Patent Document 1).
(3) A process for producing by reacting methyl chloroformate with an alcohol (see, e.g., Patent Document 2).
(4) A process for producing by reacting hexachloroacetone with an alcohol.
However, the process (1) involves problems that only cyclic carbonates can be produced and various carbonates cannot be selectively produced.
The process (2) involves problems that since it is an equilibrium reaction, a large excess of an alcohol should be used for improving the yield of the objective product; that it is difficult to separate and remove an asymmetrical carbonate compound produced as a by-product; and the like.
The process (3) involves problems that production facilities are corroded with hydrogen chloride produced as a by-product; and the like.
As the process (4), for example, the following processes have been disclosed.
(4-1) A process of reacting a vicinal diol compound (propylene glycol, etc.) with hexachloroacetone in the presence of a base catalyst (a salt of a strong base with a weak acid) to obtain a cyclic alkylene carbonate and chloroform (Patent Document 3).
(4-2) A process of reacting a vicinal diol compound (propylene glycol, etc.) with hexachloroacetone in the presence of a Group 2 or 3 metal hydrosilicate catalyst to obtain a cyclic alkylene carbonate and chloroform (Patent Document 4).
(4-3) A process of reacting hexachloroacetone with a compound having an OH group in the presence of a halogen salt catalyst to obtain a compound having a carbonate bond (Patent Document 5).
(4-4) A process of reacting hexachloroacetone with a fluorine-containing compound having an OH group to obtain a fluorine-containing compound having a carbonate bond (Patent Document 6).
In the processes (4-1) and (4-2), a cyclic carbonate compound has been obtained by the reaction of hexachloroacetone with a vicinal diol compound in the presence of a catalyst. However, according to the investigation made by the present inventors, it is expected that the direct application to the reactions of hexachloroacetone with other diols and monools may be difficult because the reaction rate of the carbonate formation reaction by intramolecular cyclization is very high in the case of a diol compound having adjacent OH groups in a vicinal position.
Moreover, in the processes (4-1) and (4-2), chloroform (non-polar solvent) formed by the reaction of hexachloroacetone with the vicinal diol compound decreases the solubility of the catalyst in the substrates to lower the yield of the objective compound, so that it is necessary to remove the chloroform by distillation during the reaction of hexachloroacetone with the vicinal diol compound. However, in order to remove the chloroform by distillation simultaneously with the reaction, a dedicated facility becomes necessary, which is industrially disadvantageous.
Further, in the process (4-1), it is described that a crown ether is effective as a phase transfer catalyst and a non-cyclic glycol ether or another ether can be used as an inert solvent. However, a crown ether has toxicity and is expensive, which are industrially disadvantageous. Also, in the case of using a solvent, it is necessary to separate the solvent from the reaction mixture after the reaction, which is industrially disadvantageous.
Also in the processes (4-3) and (4-4), for the aforementioned reason, it is necessary to remove chloroform by distillation during the reaction of hexachloroacetone with the compound having an OH group. However, the case of removing the chloroform by distillation involves the following problems.                In order to remove the chloroform by distillation simultaneously with the reaction, a dedicated facility becomes necessary, which is industrially disadvantageous.        In the case where the compound having an OH group forms an azeotrope with chloroform, the compound having an OH group as a raw material is also distilled away.        